Brake testing apparatus



2&1 1,921

Aug. 20, 1935.

G. J. THOMAS BRAKE TESTING APPARATUS Filed May 14, 929 4 Sheets-Sheet l1Aug.2@,1935. G J.THOMAS I BRAKE 'TESTINCT APPARATUS 4 Shets-Sheet 2Filed May 14, 1929 1 &m

INVEN+D R 1935. J. THOMAS 2 ,011,921

BRAKE TES TING APPARATUS Filed May 14, 1929 4 Sheets-Sheet 3 INVELN+E1Ii:

Aug. 2@, 1935. G.-J. THOMAS BRAKE TESTING APPARATUS Filed May 14, 1929 4sh t -s t 4 ILIHIH" IN EINI'EJ R aZM W 1 Patented Aug. 20, 1935 Thisinvention relates-toappa-ratus for-testing the efficiency of vehiclebrakes of the type in which a plurality of rotors are provided adaptedto receive and support the vehicle wheels and which are adapted to beconnected to equalize their speed and to be disconnected so that theymay run independently and thus enable the efficiency of each brake to bedetermined independently. In this type of machine the rotors may bearranged as or to rotate in harmonywith momentum wheels to store kineticenergy and thus render the conditions under which the test ismadesimilar to the conditions encountered when the vehicle is moving on theroad. The vehicle is anchored at the front and rear ends in orderto-maintain its wheels in engagement with the rotors.

1 When the vehicle on the apparatus and the wheels are started rotatingin harmony with the rotors the vehicle tends to move forward exerting apull upon the mechanism for anchoring the rear end or the vehicle andrelieve the strain upon the mechanism for anchoring the front end of thevehicle. However, when the vehicle brakes are applied the oppositeaction takes place andlthe strain is placed upon the mechanism foranchoring the front end of thevehicle; In using an apparatus of thistype it is commonpractice torotate the vehicle wheels in harmony withthe rotors at a rate equivalentto the travel of the vehicle upon theroad at a speed of thirty miles or more an hour. It can be appreciatedthatwhen the vehicle brakes are applied after the vehicle wheels androtors. are rotating in harmony at such a rate that the strain set upinthe mechanism foranchoring the front end of theivehicle is enormous.This sudden strain hasthe tendency to lift the frontend of the apparatusand if the anchoring mechanism inclines downwardly there is a tendencytoincrease the traction between the vehicle Wheelsandthe rotors.

.In'xtesting the brakes of vehicles of varying wheel-[base it isnecessary to adjust the relative longitudinal position of the rotorssupporting the vehicle wheels. In order to accomplish this it has beennecessary in machines as constructed heretofore to mount the frontrotors in an adjustably movable frame in spite of the factthat enormousforces are created during the test whichtendjto raise or turn the frontportion of the frame. On account of theseforces, it has been necessaryto construct the movable front frame very heavy in essential have beenvery iexpensive tQLmanug UNITED PATENT facture As a result theircost topurchasers has been very high and consequentlytheir use. has beenlimited. Moreover,.-it has been a difficult and .exi-

pensive operation toset'up and install these .machines and has-requiredthe services of a highly skilled man. These machinesoften have requiredexpensive servicingwhich has rendered theirInanufacture unattractivefinancially;

. I have discovered that the necessary weight ofa brake testingapparatus of this type. can be re ducedgreatly and consequently lowerthe cost of production by securing thefront portionot the frame to thefoundation and. arranging the rear portion of the frame for movementrelativeithereto. In accordance with: the invention the; apparatus is soconstructed that it may set up quick-- ly and thus lower the cost ofinstallation. Furithermore; the apparatus embodies certain refine--ments enabling the test of the brakes'to-.:be.made quicker and moreeasily. i

Before explaining in detail the present invention,-1t is to:beunderstood'that the invention is not limited in its application tothe .details of construction and'arrangement f parts illustratedin theaccompanying drawings, since the; invenered in view of the prior art andthe requirem thereof.

The invention will be more clearly-understood from the followingdescription-in conjunctionwlth the accompanying drawings; in which:

Fig. l is an elevational view of an apparatus embodying the inventionshowing a vehicle "positioned thereon for the-tests a 1 Fig. 'Zis anend. elevation of the same as viewed from the right of Fig; 1,1theinclined'ways being Fig. 3 is a plan' view' of the apparatuswith theclutch operating circuitshownin diagram.

Fig. i is a fragmentary sectional view showing in detail themountingforthe rotorsandin. di-

gagram the; device for indicating I when alined shafts are connected ordisconnected;

Fig. 5 is a sectionalview takenuponlthe line 5- 5,"Fig. 4. g I I .Fig. 6is a section through. the clutch mechanismtaken on line lj--6, Fig. 4

Fig. 7 is a fragmentary detail view in elevation of the countermechanism.

Fig. 8 is a sectional view taken on line 88,

Fig. 7;

Fig. 9 is a detail view of the dial;

Fig. 10 is a detail view in section of the telescoping driving shaftconnecting the front and rearunits; v,

Fig. '11 is adeta'il sectional view taken on the line ll'"ll,Fig.l;""

Figs. 12 and 13 are perspective views respecmember; 1

Fig. 14 is a fragmentary. sectional View of the shaft housing;

Fig. 15 is a detail of the lower portion of the clutch casing;

m. a. A machine constructed in'accordance with the provisions-of theinvention is illustrated in the accompanying drawings .and comprisesparallel longitudinal supports 20, such as I-beams, supporting'a'stationary front frame 2! anda movable.rear frame 22.;the. generalconstruction of iwhichissimilar. The frameZl comprises an up.-

right support 24 (see particularly Fig. 12) preferably of cast steel,secured in a similar position on each. of the supporting members 20, asby -bolts1.25.- Cross members 26 such as angle bars, extend over theuprights 24 and are secured thereto as by boltsi'land carry theforwardends of spacedtchannel members 28 forming runways forthe. vehiclewheels. The rear ends of the channel members 28. are: supportedupon theme'mbersfll by uprights'30 which are connected by a crossmember 3|. Theuprights 24 are providedwith openings 32v to receive. the housing 35which extends between and outwardly beyond the uprights 24 and isprovided with flanges 36 which areisecuredto the uprights 24, as bybolts31 (see Fig. 3); A rotorAll. adapted to store sufficient kinetic: energyfor the'purpose of the'testis r0,- tatablymounted? on anti-frictionbearings. 4i at opposite ends of the'housing 35 and projectslupriwardly-through. openings 29 in the, members 28. The bearings areheldagainst a shoulder 42 'on the "housing 35 by a collar. 43 securedupon thehousingfas by set screws 44. 1

H -The housing 35 is provided with a transverse opening or passage 45adapted to receive a casing 46, which may bedetachably secured to thehousinggzaszby bolts 19. To facilitate assembly and installation of theapparatus the casing45 ris-c'omposedof. upper and lower portions 41 and.148 respectively which maybe secured together.

rotation in suitable roller bearings 54 shimmedin anannular projection55 on the casing 45' and is provided at its inner end with abevelgear'56 adapted to meshwith the bevel'gear' 52; Female clutch'membersfio are grooved internally toreceive the splines 51 onoppositeends of the clutch .member' 50 and each is provided with anannular groove 5| adaptedtdreceive a fo'rkBZ forming one arm of abell.crank; Thebell cranks are "pivotally mountedupon pins 8 carried by 2,513 01;-

et.4 detachably mounted in lugs 63 projecting inwardly from thecasing46L The other arm 65 of the bell crank'is pivotally connected with-a'r'o'd 66 slidably. mounted in a plate 9 fixed upon a bar 68 slidablymounted in the casing and extending outwardly therefrom. To the outerend of the bar 68 is pivotally connected an operating lever I0 which ispivotally carried by lugs H on the casing 46. A spring 6 surrounds eachof the rods 56 with one end abutting the plate 9 and the other endengaging a collar 14 held upon the rod 66 by a. cotter pin. A spring 16surrounds the bar 68 and extends'between the casing 46 and the plate 9.tively of the front and rear upright supporting The inner end of the bar68 is supported in a bearing formed in the bracket 4. Alined shafts eachare provided with a reduced'portion 1- adapted to be received inopposite ends of themember 50 which serves as a [bearing therefor. Theother end of each of the shafts 80 has shrunk thereon a drive plate 84which is secured to one of the rotors 49, as by bolts 86. A plurality ofsplines 88 formed on 7 each of the shafts 80 near the inner end thereofare adapted .to be received by the grooves 89 of the femaleclutch member60 for sliding engagement therewith. 1,

In accordance with the invention the rear frame ismounted for movementtoward and away frame is similar to, the construction of the front framebutinstead of securing the supports 24 of the rear frame to the I-beams20, rollers having, flanges l adapted-to engage the I-beams from thefrontframe. The construction of this 20 are mounted upon shafts 81extending trans versely between opposite uprights 24 and rotatablymounted in bearings 99 therein. One of these, shafts is provided with asprocket wheel 91 whichis connected by a chain 98 to a sprocket wheel 99carried by a shaft VI 00 rotatably mounted in the, rear, frame and whichmay be rotated in any suitable manner, as by a crank NH. The .rear framemay be locked in any predetermined position by a suitable lockingmechanism engaging the, support 20. trated, a latch 93 is slidablymounted upon each of the uprights 24' which is provided with a lug 8|having an opening 82'to-receive the same. The latch'is presseddownwardly by a spring I94 to For this purpose, as 'illusengage any oneof the-openings 105 in the top of dle' I01, rigidly secured to the shaft9| serves as means to release the latches v93 for the purpose ofshiftingthe rear frame 22 'Any tendency of the rear. frame to rise fromthe rails 29 is prevented by brackets 94 secured to the uprights 24f andhaving urned flanges 95 engaging the under surfaceof the rails 20 .(seeFig. 2). The front ends of the ways 28' of the rear frame fit withinthelrear ends of the ways 28 of the front frame and slide thereupon whenthe rear frame is moved relative to the front frame.

way H5 in'alinement with each of the ways'28 is secured to the a rearframe 22, the opposite or lower end of each runway terminating adjacentthe floor. Abracket I I! is secured to each of the An inclinedrunrunways. I I5. at an intermediate point thereon landis provided atits lower end with a roller I 18 adapted .to engage and move alongthefloor.

connected in order to equalize the peripheral 'speedof the rotors 49 anddisconnect them when the brakes are being applied an indicator isprovided 'in accordance with the invention which willindicate'to theoperator when the alined shafts 80 are connected and; disConnectedLlnaccordance with the invention this indicator is actuated by theoperation of the clutch operating mechanism and for this purposecontacts I Miami ;I Here provided within eachcasing 45 adjacent theplate 9. .The contacts-l I0 and llIiare' com nected with red lamps H2 byconductors: M3 and ,IM respectively; Contacts,. 38 and 3,9 "are alsoprovided within each of thecasings' 46 Land a e ne ted. w thz s eenlamps 61 by electrical conductors 69 and "I3. respectively. A suitablesource-of. electrical power,herein shown as a isconnected by a universaljoint I2lto the shaft 53 of the front unit whereas the outerj endgof theshaft; I26 is connected by a universal joint I 28 to -the shaft 53 ofthe rear-unit.- Ereferably each of the shafts I and I26 are providedwith resilient members I8 (Fig. 10) adapted to engage the other andprevent wobbling and rattling.

A suitablemechanism isprovided for throwing out both clutches of thefront and rear units Simultaneously in order -to permit each of the .t.rotors :40 to rotate independently by the: kinetic energy storedtherein. The mechanism illustrated for this .purposecomprises a-solenoidI30 K596 p rticularly Fig. 5) suitably supported on theieizterior ofeach casing 46 and provided'with acore I3I projectingthrough said-casingand adapted to move to engagethe depending arm I32 of a bell crankpivotally mounted upon a,

pin I33 in the bracket 4. Theother arm, I34 of the bell crank is-adaptedjto be moved into andout of the path of the rod 88 to engage the innerend of said rod when the clutchesare engaged. The arm I34.,ofthe bellcrank normally is held in this position by a spring I35=extend ingbetweenthe arm I 32 and aprojection ont the bracket. 4. The movement ofthe bell crank due to the action of the spring I35 is limited by a 2pro-jecting from the bracket. The solenoids on eachof the casings 46 areconnected in series j io-a common electrical circuit I Il] including asuitable. source of ;electrical power, such as a battery MI, and amanually operable switch-i142 which is portable and may becarried to anydesired position by the operator During the test of the vehicle brakestheswitch I42 may be held byethe operator and actuated by-him as heapplies the brakes. H

T'In order to support the vehicle withi the wheels thereof supportedupon the rotors 4Ilsuit- "able anchoring mechanism is provided at thefront and rear of the apparatus. The anchoring mechanism at both thefront and rear (see. Figs.

1, ,2 ands) includes separate chains I46 and 'M'I secured to andextendingfrom'near opposite ends of the front axle of the vehicle andfrom the rear axle housing. f The other ends of :each. set nix-chain'sI46 and; I4] are securedito :a separate frame-I2 whichyin theform'illustrated, is'tri I angular in shape with its apexlooselyeonnect'ed to one endof a screw 3.-I Inthe mechanism for'anchoring the rearend of 'thevehicle the screwfi passeslooselyithroughan opening'ina block FI5I securedin achannel member] .53 extendingT133111 wardlyfrom the rearnframe 22 and'secured .to the ,crossmemberszfiithereof. Acrank I52 is threaded. upon the screw:.3 and is adaptedtonengage-the: block I5I to move the screw iI-therethrough and place thechains IMiand I41 under equal -tension.: If the mechanism abovedescribed was employed for both the front andfirear ends of the vehiclethere would be, atendencm when the vehiclebrakes wereapplied,-exerted.by the anchoring .mechanism. toincrease the tractionbetween thevehiclewheels and rotors supporting them-EJIlais-would .beobjectionable and for this reason means arev provided for fanchoringathe front endofthevehicle. so that the strain on .theancl'ioring means may be exerted ina Sub?" stantiallyhorizontaldirection. For this purpose, a .channelmember, .9 is securedupon the cross members 26 ,of the front frame 2 I r so as to extendforwardly therefrom. A curved channel support to is secured upon thechannel member b and braced thereon by brackets II. The support In iscurved, preferably in the formof anarc sub stantially concentric withtheifront vehicle wheels machine,v and is-provided withan elongated slot113 inrthe rear .wall thereof. A block Sis adjustably mounte'donthesupport I0 by bolts-b passing through'the slot I3 thereof and is provided with anvopening to receive loosely the screw. 3. A crank I4 isthreaded upon the screw to engage theblock 5. I I r rlnadjustable stopis provided for positioning the vehicleupon the rotors 40, Forthislpurpose, spaced brackets E5 are suitably secured to the: frontframe 2! and serve as bearings-for a cross-shaft I 6; Levers -Il -areloosely mounted I when the vehicle is operatively positioned on theupon. the shaft IS in spaced relation andare providedat their upper endswith bearings for rolls Hill-adapted to engage the front wheels of thevehicle. The lower ends of the levers I! are provided with openingsv toreceive eccentrics I8 mounted on across shaft I9 journalledjn bracketsprojecting from the front frameZI. A cranked isf xedeupon one-end oftheshaft I9 vehiclewheels. e i A. mechanisn1 'is provided forcountingthe number of revolutions or distance of travel of the vehiclewheels ai'terthe brakes areapplied. In the form; illustratedthis'mechanism' is enclosed within the h'ousing. 35. for each shaft Wandcomprises a frictionwheel Il5;(seel?igs. 4, '7 and .8)

rotatably mounted upon a shaft 34 extending vbetweenthe'free ends ofarms 58, theother ends of whichare pivotallymounted upon a stud I18 in alug H9 detach-ably carried by the housing 35.

A bell crank lever I853 is pivotally'mo'unted upon a Stud 18! detachablymounted in the'housing 35 withfonefiarrnlm arranged to engage O e of thearms 58 supporting 'the'wh'eel I'IEJJ'Ihe other arm" E83 of the bellcrank I8 9 extends down-I wardl y and isconneotedwithone end of a springI85, the other end of which is secured to a stud .I 86 fixed intl'iehousing A plunger I81 is secured atone end to the arm I83 and extendsthrough a suitableguide mine housing as with its free end adjacent theclutch member so; The 'sha ft 34 1s provided'w'ithfa bevel gear I96adapted'tomesh with a bevel gear I9I carried by aQShaft I92rotajtablymounted in the housing 35 and extending thereth rough. --Adial I93 is mounted" upon the outer end of the shaft I92 and-isprovidedwith a to turn the eccentrics I8 andthereby move the 1 rolls I68laterally towards or away from the suitable scale for indicating thedistance of travel of theivehicle wheels. A cover or casing 59 (see alsoFigs. 2'and 3) is secured on the housing 35 to enclose the -dial I93 andis provided with an opening- I95 (see particularly Fig. 7) positionedopposite the point normally occupied by the zero point on the dial whenthe latter is, in an inoper- .ative positionu The dial I93 is providedwith a weight I96 adapted normally to maintain the dial in apredetermined position.

In assembling or installing the apparatus, the mechanism which iscarried within the casing 46 is assembled in the lower portion. 48thereof, as shown most clearly in Fig. 16. The upper portion 41 is thensecured to the lower portion 48 to provide a completely assembled unitwhich can beinserted in thepassage 45 of the shaft has been moved to theproper position the handle IIlIis released and the latches 9 3 forcedinto one 'of-the openings I95 in the rails ID by the springs 94. I Itwill be understood that the rolls I68 may bebrought-to' their properposition for the vehicle to be testedprior to placing the vehicle uponthe apparatus. The vehicle is driven up the inclined runways I I5 tobring the front wheels in engagementwith the rolls I68. The front andrear ends of the vehicle are then suitably anchored to the apparatus-bythe mechanism described. In so doing it is often desirable to adjust theblock 5 so that the'front anchoring mechanism will be'positionedsubstantially in ah-orizontal plane and thereby reduce toaminimum the tendency to increasethe traction between the vehiclewheelsand the rotors due to the forces created by the application of thevehicle brakes as hereinbefore described. The crank 64 is then turned tocause the rolls I68 to moveforward away from the front wheels orthe'vehicle. The alined' shafts 8B are then connected by moving theclutch members 60 by-the movement of i the operating levers I0. clutcheshave been connected properly with the alined shafts will be'indicated'if the circuit through the green lamps indicated bythe'reference'characters 61 and the letters G in'Fig, 4 have been closed. The vehiclewheels androtors 40 are then rotated in unison prefer-ably by powerderived from the vehicle motor until they have obtained a speedequivalent to the travel of the vehicle upon the road at the rate ofthirty or more miles an hour., The operator sitting in the supportingthe friction wheel I15 thereby permitting the frictionwheel I15 to comeinto fric-w tional contact with its corresponding shaft 80 and operatethe counter mechanism to indicate the distance oftravel of the vehicleafter the brakesre p l e a In so doing the handle IOIis moved The factthat the 1. In arr-apparatus for testing the brakes of a. vehicle, thecombination of 'aframe' including an elongated housing, a rotor mountedfor rotation on saidhousing at each end thereof, alined shafts withinsaid housing, driving connections between the outer end of each shaftand the rotor adjasaidcasing for connecting and disconnecting saidshafts. 3. In an apparatus for testing the brakes of a vehicle,thecombination of a frame including elongated housing,'arotor' mountedfor rotation on said housing at each' end thereof, alined shafts withinsaid housingdriving connections for separately connecting said rotorswith said shafts, male and female clutch members within said housingadapted to connect and disconnect said alined shafts, a transverse shaftmounted in said housing, intermeshing gears'on said transverse shaft andmale clutch member, and means for engaging and disengaging saidclutch'members.

4. In an apparatus for testing the brakes of a vehicle,'the combinationof a frame including a housing providedwith a' transverse passage,alined shafts in said housing on opposite sides of said passage, acasing in said passage detachabl'y secured to saidhousing, means mountedin said casing for connecting and disconnecting said shafts comprising aclutch, a pivotally mounted leverconnected with said clutch, a movablemember,- means for resiliently connecting'said member and lever, meansform'oving said member to operate said clutch, and a spring for movingsaid member to disengage sai'd'clutch. v

5. In an apparatus for testing the brakes of a vehicle, the combinationof a frame including a housing provided with a transverse passage,

alined shafts in said housing ono'pposite sides of said passage,a'casing in said passage detachably securedto said housing, meansmounted in said I casing for connecting and disconnecting said shaftscomprising. a clutch, a pivotally mounted lever connected with saidclutch, a'movable mem ber, means for resiliently connecting said memherand lever,'mea'ns for moving said member-to operatesaid clutch, asp'ringfor moving said I 6. In an apparatus-for testingthebrakes of a vehicle,the combination of a' frarne including a housing provided with atransverse passage, alined'shafts in said housing on oppositesides ofsa'idpassage, a'casing in said passage detachably secured to saidhousing, male and female clutch members adapted to'c'onnect said shafts,means for moving saidclutch members relatively into and out ofengagement, a-transverse shaft, and

intermeshing gears on said transverse shaft and one of said clutchmembers. 7

V 7. man apparatus for testing the brakes of a vehicle, the combinationof relatively. movable frontandre'arframes each including an elongatedhousing, a rotor mounted, for rotation on each end ofeach housing,alined. shafts within s id h sin driving connecti ns for s paratelyconnecting said rotors with said shafts, male clutch member between saidshafts, female clutch members adapted to connect said male clutch memberwith said shafts, a transverse shaft mounted in each of said housings, agear on each of said transverse shafts within said housings, a gearadaptedto mesh therewith mounted on said male clutch members, andtelescoping connections of rectangular cross section between saidshafts.

8. In an apparatus for testing the brakes of a vehicle, the combinationof spaced longitudinally extending supports, front and rear frames eachincluding an upright similarly positioned on each of said supports,cross members connecting similarly positioned supports and extendingoutwardly therefrom, longitudinally extending channel members carried bysaid cross members, an elongated housing extending through and connectedto similarly positioned uprights, a rotor mounted for rotation on eachend of each housing, means for connecting and disconnecting said rotors,means for securing said front frame to said supports, and means formounting said rear frame for movement on said supports.

9. ,In an apparatus for testing the brakes of a vehicle, the combinationof a frame, a pair of rotors rotatably mounted in said frame adapted toreceivethe wheels of a'vehicle, and means for anchoring a vehicle onsaid rotors comprising a screw, a member pivotally connected to saidscrew, and a chain connected to and extending from the vehicle nearopposite sides thereof and connected to said membenand an adjustableconnection between said screw and frame comprising a support extendingupwardlyfrom said frame, a block adjustably mounted on said sup-' port,and means for adjusting said screw relative to be moved into and out ofrotative connection" with said shaft, a rotatable indicator, drivingconnections between said member and indicator, and means positioned inthe path of movement of said clutch adapted to be actuated thereby tocause engagement of said member with said shaft.

GEORGE J. THOMAS.

